1. Field Of The Invention
This invention relates to a processing machine for boiled crab, lobster and other crustacean comprising a shell crushing means and a subsequent separation means in which the meat is separated from the shell fragments, at least partially, through a centrifugal force effect, said separation means comprising a rotary tray adapted to be supplied with a mixture of meat and shells and wherein a number of upright (vertical or steeply inclined) separation-wall-defining adjacent members are arranged along the path of a closed ring, the spacing therebetween being such that meat may penetrate, but where almost all the hard shell fragments are unable to pass between said adjacent members, the separated meat being collected within an annular space externally of said adjacent members.
2. Description Of The Prior Art
A number of crab processing and similar machines are known in the art for the manufacture of a processed product comprising crab meat or similar meat, for example meat of lobster or other crustacean.
One crab processing machine known in the art utilises a separation operation based on centrifugal techniques. This machine comprises a centrifuge the design of which is only intended to separate/cleanse the carapace (or "main body") of the shell. However, since separation is desirable, not only of the carapace, but also the major appendages (claws) and minor appendages (legs) in one and the same separation operation, this known machine is of limited application. Its processing capacity is also small, and the operation of the machine requires considerable manual effort.
Another crab processing machine known in the art utilises water jets to separate the crab meat from the shell fragments. The water consumption of this machine is so great that the aromatic components of the crab meat are diluted by the rinse water and may even dissolve in it. After going through this separation operation the crab has therefore lost such a considerable portion of its natural and characteristic aroma and taste that a special crab concentrate must be added, a step which generally impairs the meat's quality--including its taste quality--as the crab meat after addition of the concentrate has a "watery" or bland taste. This known machine, too, is dependent for its operation on considerable manual labour since it takes several persons to work it.
From U.S. Pat. No. 3,266,542 is known a machine which is designed to separate fragments of bone, cartilage and sinew from finely ground meat. This known machine with its relatively complex design is set up for the processing of very finely ground meat of fowl, domestic animals or fish, and imparts an even finer grinding to the meat during processing. This additional fine-grinding operation is undesirable in the case of crab meat. Also, this known machine is far too complicated for application to the present purpose.
U.S. Pat. No. 3,266,543 discloses a machine which structurally and functionally differs only in minor details from the machine disclosed in U.S. Pat. No. 3,266,542.
The U.S. Pat. No. 1,565,342 shows a low-capacity domestic appliance for the shelling of crustacea, comprising a rotary container, and wherein the separation means for separating meat from shells is formed by a number of pins (8) arranged along the path of a closed ring, the spacing there-between being such that the meat may penetrate whereas the thicker shell fragments are prohibited from entering in between said pins. Said pins have no self-motion, i.e. they rotate together with the container, but they are stationary in relation to said container.
It appears from the specification of this patent that the shells are removed from the appliance in an extremely cumbersome way. Such an appliance has, therefore, a very low capacity as compared with a device having the same dimensions but being constructed in accordance with the present application.
The U.S. Pat. No. 3,229,325 discloses a very similar construction, but the function is quite different. While the present invention and the one according to U.S. Pat. No. 1,565,342 work on an intimate mixture of crab meat and shell fragments, the machine according to U.S. Pat. No. 3,229,325 operates with holders for large crab pieces wherein the meat is contained within the associated shell portions (see specification and especially FIGS. 2, 4 and 5). After the crab meat has been separated from its associated shell piece by centrifugal force effect, said shell piece will remain within its holder means, wherefrom it subsequently must be removed individually. This limits the capacity of this known domestic appliance substantially. The shelling operation of this known device is restricted to shell pieces containing meat wherein access to all contained meat has been made available previously. A crab carapace must, therefore, in order to enable appropriate processing in a machine of this known kind, be cut open in all directions, and then it will probably, paradoxically, be quite unfit for this prior art separation operation.